Digital geometric-sequence control technique for bidirectional dual active bridge DC-DC converters used in future electric vehicles

Bidirectional DC-DC converters are widely used in different applications such as energy storage systems, Electric Vehicles (EVs), UPS, etc. In particular, future EVs require bidirectional power flow in order to integrate energy storage units into smart grids. These bidirectional power converters provide Grid to Vehicle (V2G)/ Vehicle to Grid (G2V) power flow capability for future EVs. Generally, there are two control loops used for bidirectional DC-DC converters: The inner current loop and The outer loop. The control of DAB converters used in EVs are proved to be challenging due to the wide range of operating conditions and non-linear behavior of the converter. In this thesis, the precise mathematical model of the converter is derived and non-linear control schemes are proposed for the control system of bidirectional DC-DC converters based on the derived model. The proposed inner current control technique is developed based on a novel Geometric-Sequence Control (GSC) approach. The proposed control technique offers significantly improved performance as compared to one for conventional control approaches. The proposed technique utilizes a simple control algorithm which saves on the computational resources. Therefore, it has higher reliability, which is essential in this application. Although, the proposed control technique is based on the mathematical model of the converter, its robustness against parameter uncertainties is proven. Three different control modes for charging the traction batteries in EVs are investigated in this thesis: the voltage mode control, the current mode control, and the power mode control. The outer loop control is determined by each of the three control modes. The structure of the outer control loop provides the current reference for the inner current loop. Comprehensive computer simulations have been conducted in order to evaluate the performance of the proposed control methods. In addition, the proposed control have been verified on a 3.3 kW experimental prototype. Simulation and experimental results show the superior performance of the proposed control techniques over the conventional ones.

The Impact of Geographic Mobility on Canadian Military families and their Children’s Access Special Education Services

To achieve academic success, children with learning-related disabilities often receive special education supports at school. Currently, Canada does not have a federal department or integrated national system of education. Instead, each province and territory has a separate department or ministry that is responsible for the organization and delivery of education, including special education, at the elementary level. At the macro (national) level, inclusive education is the policy across Canada. However, each province and territory has its own legislation, definitions, and policies mandating special education services. These variations result in little consistency at the micro (individual school) level. Differences between eligibility requirements, supports offered, and delivery methods may present challenges for highly mobile families who must navigate new special education systems on behalf of their children with medical or learning challenges. One of the defining features of the Canadian military lifestyle is geographic mobility. As a result, many families are tasked with navigating new school systems for their children, a task that may be more difficult when children require special education services. The purpose of this study is to explore the impact of geographic mobility on Canadian military families and their children’s access to special education services. The secondary objective was to gain insight into supports that helped facilitate access to services, as well as supports that participants believe would have helped facilitate access. A qualitative approach, interpretive phenomenological analysis (IPA), was employed due to of its focus on individuals’ experiences and their understandings of a particular phenomenon. IPA allowed participants to reflect on the significance of their experiences, while the researcher engaged with these reflections to make sense of the meanings associated with their experiences. Nine semi-structured interviews were conducted with civilian caregivers who have a child with special education needs. An interview guide and probes were used to elicit rich, detailed, first-person accounts of their experiences navigating new special education systems. The main themes that emerged from the participants’ combined experiences addressed the emotional components of experiencing a transition, factors that may facilitate access to special education services, and career implications associated with accessing and maintaining special education services. Findings from the study illustrate that Canadian families experience many, and often times severe, barriers to accessing special education services after a posting. Furthermore, the impacts reported throughout the study echo the existing American literature on geographic mobility and access to special education services. Building on the literature, this study also highlights the need for further research exploring factors that create unique barriers to access in a Canadian context, resulting from the current special education climate, military policies, and military family support services.

Optical properties of chiral thin films and microparticles

In this work I study the optical properties of helical particles and chiral sculptured thin films, using computational modeling (discrete dipole approximation, Berreman calculus), and experimental techniques (glancing angle deposition, ellipsometry, scatterometry, and non-linear optical measurements). The first part of this work focuses on linear optics, namely light scattering from helical microparticles. I study the influence of structural parameters and orientation on the optical properties of particles: circular dichroism (CD) and optical rotation (OR), and show that as a consequence of random orientation, CD and OR can have the opposite sign, compared to that of the oriented particle, potentially resulting in ambiguity of measurement interpretation. Additionally, particles in random orientation scatter light with circular and elliptical polarization states, which implies that in order to study multiple scattering from randomly oriented chiral particles, the polarization state of light cannot be disregarded. To perform experiments and attempt to produce particles, a newly constructed multi stage thin film coating chamber is calibrated. It enables the simultaneous fabrication of multiple sculptured thin film coatings, each with different structure. With it I successfully produce helical thin film coatings with Ti and TiO_{2}. The second part of this work focuses on non-linear optics, with special emphasis on second-harmonic generation. The scientific literature shows extensive experimental and theoretical work on second harmonic generation from chiral thin films. Such films are expected to always show this non-linear effect, due to their lack of inversion symmetry. However no experimental studies report non-linear response of chiral sculptured thin films. In this work I grow films suitable for a second harmonic generation experiment, and report the first measurements of non-linear response.

Surface wave and storm surge prediction during Hurricane Sandy

Hurricane Sandy was the largest storm on historical record in the Atlantic Ocean basin with extensive coastal damage caused by large waves and high storm surge. The primary objectives of this thesis are to compare and evaluate three different spatially-varying surface wind fields of Hurricane Sandy to investigate the impact of the differences between the complex wind fields on predictions of the sea surface evolution, and to evaluate the impact of the storm on the hydrodynamics in Great South Bay (GSB) and the discharge of ocean water into the back-barrier bay from overwash over Fire Island. Three different spatially-varying surface wind fields were evaluated and compared to wind observations, including the parametric Holland (1980) model (H80), the parametric Generalized Asymmetric Holland Model (GAHM), and results from the WeatherFlow Regional Atmospheric Modelling System (WRAMS). The winds were used to drive the coupled Delft3D-SWAN hydrodynamic and ocean wave models on a regional grid. The results indicate that the WRAMS wind field produces wave model predictions in the best agreement with significant wave height observations, followed by the GAHM and H80 wind fields and that a regional atmospheric wind model is best for hindcasting hurricane waves and water levels when detailed observations are available, while a parametric vortex model is best for forecasting hurricane sea surface conditions. Using a series of four connected Delft3D-SWAN grids to achieve finer resolution over Fire Island and GSB, a higher resolution WRAMS was used to predict waves and storm surge. The results indicate that strong local winds have the largest influence on water level fluctuations in GSB. Three numerical solutions were conducted with varying extents of barrier island overwash. The simulations allowing for minor and major overwash indicated good agreement with observations in the east end of GSB and suggest that island overwash provided a significant contribution of ocean water to GSB during the storm. Limiting the overwash in the numerical model directly impacts the total discharge into GSB from the ocean through existing inlets. The results of this study indicate that barrier island overwash had a significant impact on the water levels in eastern GSB.

The Evolution and Reform of Summary Trials in Canadian Military Justice

There is a place where a Canadian citizen can be sent to 30 days detention, by someone who is not a judge, without being represented by counsel, and without having a meaningful right to appeal. It is the summary trial system of the Canadian Armed Forces. This thesis analyses that system and suggests reforms. It is aimed at those who have an interest in improving the administration of military justice at the unit level but want to sufficiently understand the issues before doing so. Through a classic legal approach with elements of legal history and comparative law, this study begins by setting military justice in the Canadian legal firmament. The introductory chapter also explains fundamental concepts, first and foremost the broader notion of discipline, for which summary trial is one of the last maintaining tools. Chapter II describes the current system. An overview of its historical background is first given. Then, each procedural step is demystified, from investigation until review. Chapter III identifies potential breaches of the Charter, highlighting those that put the system at greater constitutional risk: the lack of judicial independence, the absence of hearing transcript, the lack of legal representation and the disparity of treatment between ranks. Alternatives adopted in the Canadian Armed Forces and in foreign jurisdictions, from both common law and civil law traditions, in addressing similar challenges are reviewed in Chapter IV. Chapter V analyses whether the breaches could nevertheless be justified in a free and democratic society. Its conclusion is that, considering the availability of reasonable alternatives, it would be hard to convince a court that the current system is a legitimate impairment of the individual’s legal rights. The conclusion Chapter presents options to address current challenges. First, the approach of ‘depenalization’ taken by the Government in recent Bill C-71 is analysed and criticised. The ‘judicialization’ approach is advocated through a series of 16 recommendations designed not only to strengthen the constitutionality of the system but also to improve the administration of military justice in furtherance of service members’ legal rights.

AN INVESTIGATION ON ROUTINE FOLLOW-UP CARE FOR HEAD AND NECK CANCER

BACKGROUND: Follow-up care aims to provide surveillance with early detection of recurring cancers and to address treatment complications and other health issues in survivorship. It is assumed that follow-up care fulfills these aims, however little evidence supports routine surveillance detecting curable disease early enough to improve survival. Cancer survivors are a diverse patient population, suggesting that a single follow-up regimen may not meet all patients’ follow-up needs. Little is known about what effective follow-up care should include for head and neck cancer patients in a Canadian setting. Identification of subgroups of patients with specific needs and current practices would allow for hypotheses to be generated for enhancing follow-up care. OBJECTIVES: 1a) To describe the follow-up needs and preferences of head and neck cancer patients, 1b) to identify which patient characteristics predict needs and preferences, 1c) to evaluate how needs and preferences change over time, 2a) to describe follow-up care practices by physician visits and imaging tests, and 2b) to identify factors associated to the delivered follow-up care. METHODS: 1) 175 patients who completed treatment between 2012 and 2013 in Kingston and London, Ontario were recruited to participate in a prospective survey study on patients’ needs and preferences in follow-up care. Bivariate and multivariate analyses were employed to describe patient survey responses and to identify patient characteristics that predicted needs and preferences. 2) A retrospective cohort study of 3975 patients on routine follow-up from 2007 to 2015 was carried out using data linkages across registry and administrative databases to describe follow-up practices in Ontario by visits and tests. Multivariate regression analyses assessed factors related to follow-up care. RESULTS: 1) Patients’ needs and preferences were wide-ranging with several characteristics predicting needs and preferences (ORECOG=2.69 and ORAnxiety=1.13). Needs and preferences declined as patients transitioned into their second year of follow-up (p<0.05). 2) Wide variation in practices was found, with marked differences compared to existing consensus guidelines. Multiple factors were associated with follow-up practices (RRTumor site=0.73 and RRLHIN=1.47). CONCLUSIONS: Patient characteristics can be used to personalize care and guidelines are not informing practice. Future research should evaluate individualized approaches to follow-up care.

Adversity in early adolescence alters female rats' anxiety-related behaviours and serotonergic innervation profiles in adulthood

Stress during early development produces lasting effects on psychopathological outcomes. The impact of prior intermittent, physical stress (IPS) during early-adolescence (PD 22-33) on anxiety-related behaviour of female rats was analyzed in adulthood. After behavioural testing, serotonergic innervation was evaluated using immunohistochemistry for the serotonin transporter (SERT) in the medial prefrontal cortex (mPFC) and ventral hippocampus. Administration of IPS (i.e., water immersion, elevated platform, foot shock) in early adolescence increased rats’ anxiety-like behaviour in the elevated plus-maze but had no effects in the shock-probe burying test. In the social interaction test, IPS decreased social interaction, and this effect was driven by selective decreases in the duration of playfighting with no evident changes in contact or investigative behaviour. Selective stress-induced increases in SERT-immunoreactive axon density were found in the infralimbic (IL) subregion of the mPFC, but not in the cingulate or prelimbic (PL) subregions. IPS in early adolescence did not affect serotonergic innervation profiles in any sub-fields of the ventral hippocampus. The findings confirm and extend on earlier evidence that stress during early adolescence promotes the emergence of an anxious phenotype, and provide novel evidence that these effects may be mediated, at least in part, by increased serotonergic innervation of the IL mPFC.

Disability in the Digital Age: Reconfiguring Access, Inclusion and Equality

There is an abundance of research that examines disability and technology in the context of computers and the Internet, however few have examined disability and mobile devices. Also largely absent from existing literature are the voices of disabled people themselves. This dissertation draws upon science and technology studies (STS) and disability studies to address these gaps by conducting in-depth qualitative research that examines disabled people’s experiences using smartphones and tablets. At its core, this dissertation aims to provide insight on the following: 1) an understanding of how disability is perceived in the digital age and the subjective meanings of access, inclusion and equality; 2) the ways in which mobile devices impact the lived experience of disability; and 3) how perspectives in disability studies and STS can be applied to understand the relationship between the body, disability and technology. The empirical contribution of this research draws from participant diaries and interviews with disabled people, as well as from open-ended questionnaires completed by mobile app developers. The concept of ‘subjectivities of disability’ is introduced to refer to the uniquely personal and individual experience of disability. Findings reveal that mobile device use amongst disabled people redefines their subjectivities of disability through socio-technical interactions whereby disabled people use their devices in ways that are integrated into their everyday lives and positively shapes how they view themselves in relation to their experience of disability. The responses from app developers reveal that there is a place for disability in the mobile market and that disabled people play a key role in making apps accessible. The data suggests that mobile devices facilitate access, inclusion and equality by integrating the body in ways that recognize and accommodate diversity. The results furthermore make it clear that the interaction between disabled people and mobile devices takes on an embodied and social characteristic. This research concludes that both on an individual level and collectively, disabled people are engaging with digital artifacts in ways that promote agency and independence as well as reshaping how disability is experienced and perceived in the digital age.

Using phase-space localized basis functions to obtain vibrational energies of molecules

For decades scientists have attempted to use ideas of classical mechanics to choose basis functions for calculating spectra. The hope is that a classically-motivated basis set will be small because it covers only the dynamically important part of phase space. One popular idea is to use phase space localized (PSL) basis functions. This thesis improves on previous efforts to use PSL functions and examines the usefulness of these improvements. Because the overlap matrix, in the matrix eigenvalue problem obtained by using PSL functions with the variational method, is not an identity, it is costly to use iterative methods to solve the matrix eigenvalue problem. We show that it is possible to circumvent the orthogonality (overlap) problem and use iterative eigensolvers. We also present an altered method of calculating the matrix elements that improves the performance of the PSL basis functions, and also a new method which more efficiently chooses which PSL functions to include. These improvements are applied to a variety of single well molecules. We conclude that for single minimum molecules, the PSL functions are inferior to other basis functions. However, the ideas developed here can be applied to other types of basis functions, and PSL functions may be useful for multi-well systems.

Redefining Attitude Importance: The Possible Existence of Associative and Subjective Types of Importance Under a Global Definition

Traditionally, importance has been measured using subjective measures. The present thesis explores the possibility of a second type of importance, designated as “associative importance”. A new measure, the IIAT, was designed to capture the strength of association between an object and the attribute of importance. This thesis then evaluated the validity of the IIAT via an intervention paradigm in 2 studies, and by using the measure to predict a memory outcome in 2 other studies. Subjective measures of importance were also included in these studies and correlations between subjective measures and IIAT results were examined. Across all 4 studies, subjective-objective correlations were weak to modest and non-significant. The intervention studies provided promising evidence that interventions do affect associative importance as measured by the IIAT. The prediction studies provided somewhat mixed, but encouraging evidence that the IIAT may be able to predict memory performance. Notably, subjective measures were not able to predict memory performance at all, whereas the IIAT was able to predict some memory indices. Overall, there is some evidence supporting the existence of an associative importance construct, and that the IIAT provides valid results that are nonetheless different from that of subjective measures of attitude importance.

(MIS)PERCEIVED DRINKING NORMS AND HAZARDOUS DRINKING BEHAVIOURS IN UNIVERSITY FIRST-YEAR UNDERGRADUATE STUDENTS AND THE EFFECTS OF GENDER

Purpose: Across Canada, undergraduate university students are one of the highest alcohol-consuming populations. Many students engage in hazardous drinking and are at risk for negative health and social consequences. Social Norms Theory suggests that students’ overestimation of drinking norms can result in an increase in their drinking behaviour. As of yet, none of the literature addresses the possible link between drinking norm (mis)perception and hazardous drinking in a Canadian undergraduate context. This is the first Canadian study to examine this potential association in first-year undergraduate students across multiple universities using gender as an effect modifier. Methods: Using data collected by the Caring Campus Project, for 2347 first-year students from three Canadian universities, I evaluated the prevalence of drinking norm misperceptions by site and gender. Using multiple-logistic regression models, I analyzed the relationship between misperceived drinking norms and hazardous drinking behaviours (assessed via AUDIT-C). Results: The proportion of students who overestimated drinking and binge drinking frequency norms varied by site and gender. There was a positive relationship between overestimated drinking/ binge drinking frequency norms and hazardous drinking, modified by gender. Controlling for living arrangement and site, the odds of female students being hazardous drinkers increased by a factor of 2.27 (CI: 1.73-2.99) when the drinking frequency norm was overestimated. A non-significant association was found for male students. Among female students, when living arrangement and site were controlled, the odds of being a hazardous drinker were 1.83 (0.84-3.95) and 2.69 (1.24-5.83) times greater when the drinking frequency norm was perceived at “2-4 times per month” and “2 or more times per week”, respectively. Among male students, when living arrangement, previous residence and site were controlled, the odds of being a hazardous drinker were 4.03 (2.62-6.19) and 8.54 (5.41-13.49) times greater when the binge drinking frequency norm was perceived at “2-4 times per month” and “2 or more times per week”, respectively. Conclusion: This novel study enhances the understanding of the association between (mis)perceived drinking norms and drinking behaviours in Canadian undergraduate students. The demonstrated importance of gender and site provides a strong impetus for Canadian universities to develop targeted alcohol reduction interventions.

RELIBILITY ANALYSIS OF SIMPLE SLOPES AND SOIL-STRUCTURES WITH LINEAR LIMIT STATES

The first objective of this research was to develop closed-form and numerical probabilistic methods of analysis that can be applied to otherwise conventional methods of unreinforced and geosynthetic reinforced slopes and walls. These probabilistic methods explicitly include random variability of soil and reinforcement, spatial variability of the soil, and cross-correlation between soil input parameters on probability of failure. The quantitative impact of simultaneously considering the influence of random and/or spatial variability in soil properties in combination with cross-correlation in soil properties is investigated for the first time in the research literature. Depending on the magnitude of these statistical descriptors, margins of safety based on conventional notions of safety may be very different from margins of safety expressed in terms of probability of failure (or reliability index). The thesis work also shows that intuitive notions of margin of safety using conventional factor of safety and probability of failure can be brought into alignment when cross-correlation between soil properties is considered in a rigorous manner. The second objective of this thesis work was to develop a general closed-form solution to compute the true probability of failure (or reliability index) of a simple linear limit state function with one load term and one resistance term expressed first in general probabilistic terms and then migrated to a LRFD format for the purpose of LRFD calibration. The formulation considers contributions to probability of failure due to model type, uncertainty in bias values, bias dependencies, uncertainty in estimates of nominal values for correlated and uncorrelated load and resistance terms, and average margin of safety expressed as the operational factor of safety (OFS). Bias is defined as the ratio of measured to predicted value. Parametric analyses were carried out to show that ignoring possible correlations between random variables can lead to conservative (safe) values of resistance factor in some cases and in other cases to non-conservative (unsafe) values. Example LRFD calibrations were carried out using different load and resistance models for the pullout internal stability limit state of steel strip and geosynthetic reinforced soil walls together with matching bias data reported in the literature.

The relationship between non-suicidal self-injury and suicidality

The overall purpose of this study was to explain the overlap and distinctiveness of non-suicidal self-injury (NSSI) and suicidality from a diathesis-stress perspective. The first part of this study evaluated the third variable theory as an explanation for the high rates of lifetime co-occurrence between NSSI and suicidality. Specifically, it was hypothesized that these forms of self-harm share a common vulnerability profile comprised of five affective, cognitive and behavioural diatheses. The second part of this study tested the hypothesis that NSSI and suicidality become distinguishable on the basis of immediate, proximal stressors, namely psychache and survival and coping beliefs (SCB). Participants (N = 262) were community individuals aged 16-24 years who reported either no history of self-harm (i.e., no history of NSSI, suicidality, or both), a history of NSSI, suicidality or both, or current NSSI-only or current NSSI+suicidality. They were recruited online to complete an online battery of questionnaires. Using a set of discriminant function analyses, it was found that the vulnerability profile was unable to distinguish between the three self-harm groups, but was able to differentiate the no self-harm group from a collated self-harm group. Result patterns were also analyzed for gender differences. It was also found that a current NSSI+suicidality group exhibited significantly higher psychache and lower SCB (for women only) than a current NSSI-only group. These results suggest that NSSI and suicidality may tend to co-occur because they have similar long-term diatheses, but that they may become more distinct with respect to immediate psychological stressors.

NON-FULL-TIME COLLEGE PROFESSORS: A NARRATIVE INQUIRY INTO THE NON-FULL-TIME FACULTY ROLE

The rate of non-full-time faculty members has increased rapidly over the last decade (Louis, 2009; MacKay, 2014; Meranze & Newfield, 2013), as the post-secondary landscape of fluctuating enrolment, fiscal and operational challenges, and the requirement to hire specialized skill sets have required institutions to rely heavily on this demographic. In the Ontario Colleges of Applied Arts and Technology (CAATs) system, institutions have tried to preserve and enhance educational quality with fewer resources through greater reliance on non-full-time faculty. The purpose of this study was to explore the perceptions and experiences of teaching and support of non-full-time faculty at one Eastern Ontario college. Employing a narrative inquiry methodology, data were collected from four participants through their writing three individual letters at the end of each month and participating in one interview at the end of the contract period. The data were analyzed and coded. This analysis revealed five themes: motivation, connection and engagement, compensation, teaching and development, and performance evaluation. Differences in the participants’ perceptions tended to reflect divergences across career stage: retired versus early career. The compensation package provided to non-full-time faculty was considered inadequate for those in the early career stage, especially comparing it to that of full-time faculty. In addition, the amount of previous teaching experience was an important indicator for the appropriate level of teaching resources and support provided by the institution. The newer faculty members required a higher level of support to combat feelings of role isolation. The temporary nature of the role made it difficult to establish a feeling of a strong connection to the institution and subsequently opportunities to engage further to deepen the relationship. Despite these differences across participants, autonomous motivators were consistent across all narratives, as participants expressed their desire to teach and share their knowledge to help students achieve their goals. Participants concluded their narratives by sharing future advice for faculty interested in pursuing the role. The narratives provided areas for improvement that would help increase the level of job satisfaction for non-full-time college faculty members: (a) establishing a more thorough performance evaluation process to align with institutional supports, (b) offering more diverse teaching resources to better prepare faculty and enhance teaching practices, (c) overhauling the compensation package to better recognize the amount of time and effort spent in the role and aligning with the compensation provided to full-time faculty, and (d) including rewards and incentives as part of the compensation package to enhance the level of commitment and availability for the role. These changes might well increase the job satisfaction and improve the retention of non-full-time faculty members.

A case study on a design-informed developmental evaluation

Developmental evaluation (DE) is an evaluation approach that aims to support the development of an innovation (Patton, 1994, 2011). This aim is achieved through supporting clients’ information needs through evaluative inquiry as they work to develop and refine the innovation. While core concepts and principles are beginning to be articulated and refined, challenges remain as to how to focus a developmental evaluation beyond those knowledge frameworks most immediate to clients to support innovation development. Anchoring a DE in knowledge frameworks other than those of the clients might direct attention to issues not yet obvious to clients, but which might further the goal of supporting innovation development if attended to. Drawing concepts and practices from the field of design may be one avenue with which to inform developmental evaluation in achieving its aim. Through a case study methodology, this research seeks to understand the nuances of operationalizing the guiding principles of DE as well as to investigate the utility, feasibility, and consequences of integrating design concepts and practices into developmental evaluation (design-informed developmental evaluation, “DI-DE”). It does so by documenting the efforts of a design-informed developmental evaluator and a task force of educators and researchers in a Faculty of Education as they work to develop a graduate-level education program. A systematic review into those purposeful efforts made to introduce DI-DE thinking into task force deliberations, and an analysis into the responses and consequences of those efforts shed light on what it had meant to practice DI-DE. As a whole, this research on evaluation is intended to further contemporary thinking about the closely coupled relationship between program development and evaluation in complex and dynamic environments.